This disclosure relates generally to the field of digital photography. More particularly, but not by way of limitation, this disclosure relates to still image stabilization techniques and improved processing pipelines therefor. As used herein, image stabilization refers to a collection of techniques for reducing motion-induced blurring during image capture operations. Such motion may result from the movement of the camera, objects in the scene, or both. Further details regarding still image stabilization processes may be found in commonly-assigned U.S. patent application Ser. No. 13/911,873, entitled, “Reference Frame Selection for Still Image Stabilization,” which application is hereby incorporated by reference in its entirety. Further details regarding still image stabilization processes may also be found in commonly-assigned U.S. patent application Ser. No. 13/911,793, entitled “Image Registration Methods For Still Image Stabilization,” and in commonly-assigned U.S. patent application Ser. No. 13/911,740, entitled “Methods Of Image Fusion For Image Stabilization.”
Taking high quality photographs in low ambient light conditions, or photographing dynamic scenes (e.g., sport scenes) is challenging due to camera motion and/or the motion of objects within a scene during image capture. One way to reduce motion blur without amplifying an image's noise is to capture and fuse together multiple, short exposed images of the scene. Such operations are often called ‘Still Image Stabilization.’ While shortening image exposure times can reduce motion blur artifacts, it does so at the expense of a noisier and/or darker image.
A common approach to image stabilization consists of (1) selecting a reference image from a set of multiple short exposed images, (2) globally registering all non-reference images with the reference image, and (3) synthesizing an output image by fusing all captured images to the reference image. In this way, the output image represents the scene as it was at the time the reference image was captured, where non-reference images are used to reduce the noise in the reference image by averaging/merging multiple observations of each reference pixel across all images. A common approach to selecting the reference image is to base the selection on a quality criterion that is evaluated for each image independently (e.g., image sharpness).
Such an approach to still image stabilization can often be computationally expensive and/or inefficient and lead to undesirable consequences, such as increased shot-to-shot time intervals. Thus, it would be beneficial to provide an improved still image stabilization pipeline that interleaves image processing operations and image capture operations to reduce shot-to-shot time intervals and more efficiently utilize post-processing units.